Kampo medicines, which are bulky and compounded in large amounts, increase the sizes of tablets prepared by a direct compression tableting method. Such large sizes of the tablets lead to difficulties in administration thereof. For this reason, a wet granulation method is used in preparation of tablets containing Kampo medicines. At this time, extract powders or the like, when compounded, exhibit stickiness or moisture absorbing properties, causing low granulation yield, broad particle size distribution, poor fluidity of the resulting granules, a large variation in the weight of tablet in pressing, and the like. In addition, sticky ingredients delay disintegration of the tablets. To solve these problems, a method of compounding a microcrystalline cellulose is known.
Patent Literature 1 discloses use of a microcrystalline cellulose that can improve compactibility and disintegration properties in preparation by a direct compression tableting method.
Patent Literature 2 discloses a tablet including a microcrystalline cellulose and an inorganic compound, and prepared by direct compression tableting of the microcrystalline cellulose and the inorganic compound.
Besides, Patent Literatures 3 to 6 disclose cellulose powders, which are known as excipients which enhance compactibility.
Patent Literature 7 describes compounding of cellulose glycolic acid and sodium hydrogen carbonate during wet granulation that can improve the disintegration properties and dissolution of Kampo extract powders.